Recently, implant surgery carried out for the placement of artificial teeth has been rapidly prevailed and considered as one of general dental surgery.
So as to conduct the implant surgery, generally, a groove into which an implant fixture is embedded is first formed on an alveolar bone by means of a drill.
If it is desired to form a hole for placing the implant fixture into the alveolar bone, since the cutting resistance is substantially high, a small hole is first formed and is expanded gradually to a large size. To do this, a plurality of drills having the same length as each other but different diameters from each other, that is, having a small diameter through a desired diameter are used sequentially to cut the alveolar bone and to form the implant placement hole.
For the purpose of removing the above-mentioned inconveniences, accordingly, there have been proposed many studies as follows:
As one example of the prior arts, there is provided Korean Patent No. 100759261 disclosing an implant drill which includes: a body having a bone accommodating portion formed at the inside thereof, in which an alveolar bone is accommodated upon the formation of a hole on the alveolar bone; a plurality of cutting blades formed on the end portion of the body and forming the hole on the alveolar bone during the rotation of the body; and a plurality of bone discharging passages formed depressedly from the surface of the body with a given angle twisted with respect to the outer periphery of the body so as to guide discharge of the bone fragments caused from the formation of the hole on the alveolar bone.
As another example of the prior arts, there is provided Korean Patent No. 100985604 disclosing a hollow drill for maxillary sinus lift which includes: a cylindrical cutting part having a hollow portion formed therein; a stopper detachably mounted on the outer periphery of the cutting part and having a hollow portion formed therein; a stopper support part disposed on one side end portion of the cutting part; and a shank part disposed on the stopper support part, wherein the cutting part has a cutting blade and a cut material discharging hole formed on the lower portion of the cutting blade and having a hollow portion communicating with the outside through the side of the cutting part, the stopper has a longitudinal length allowing the cutting blade to be exposed by a desired cutting depth, and the stopper support part has a support projection formed to prevent the stopper from being pushed in a longitudinal direction.
As another example of the prior arts, there is provided Korean Patent No. 100946269 disclosing an implant drill which includes: a punched body having a cutter disposed at one end portion thereof so as to punch an alveolar bone and a through hole formed at the other end portion thereof; and a rod body coupled to one end portion of the punched body in such a manner as to be near and separated to and from the through hole of the punched body so as to adjust the depth of the hole punched on the alveolar bone during the formation of the hole.
As yet another example of the prior arts, there is provided Korean Patent Application Laid-Open No. 10-2010-0008095 disclosing a drill for implant surgery for punching alveolar bone which includes: a body having a shape of a hollow pipe and a cutting blade formed along the end portion thereof; a connector coupled to the lower portion of the body in such a manner as to be mounted on a dental handpiece; a protruding member adapted to be inserted into the body in a state of being elastically supported against in such a manner as to be movable into and out of the body; and a stopper having a shape of a hollow pipe and adapted to be exchangeably mounted on the outer peripheral surface of the body in such a manner as to allow the body to be inserted into the alveolar bone by a given depth, the stopper having a compression part disposed at the center thereof so as to compress the stopper to a given height.
As still another example of the prior arts, there is provided Korean Patent Application Laid-Open No. 10-2009-0098428 disclosing a hollow drill for maxillary sinus lift which includes: a cutting part having a cutting blade and a cut material discharging hole formed on the lower portion of the cutting blade and having a hollow portion communicating with the outside through the side of the cutting part; a stopper having a longitudinal length allowing the cutting blade to be exposed by a desired cutting depth; and a stopper support part having a support projection formed to prevent the stopper from being pushed in a longitudinal direction.
As yet still another example of the prior arts, there is provided Korean Utility Model Registration No. 200323647 disclosing an implant drill which includes: a cylindrical body having an open portion at the bottom surface thereof; a basic blade having screw threads formed repeatedly along the outer periphery of the open portion of the body; and a vertical blade formed along the inner periphery of the body in such a manner as to be upright toward the open portion of the body.
As still another example of the prior arts, there is provided Korean Utility Model Registration No. 200230475 disclosing a drill stopper for implant surgery adapted to have a hole formed to an accurate depth at a portion where a tooth is lost, which includes: a stopper having a shape of a cylinder open at the top and bottom surface thereof, a plurality of through holes formed along the side periphery thereof so as to form a fastening portion, and a tape formed along the top portion of the lower portion thereof, so that if a hole is formed to a given depth, the stopper is gently contacted with the top surface, that is, irregular surface, of a portion from which a tooth is extracted, to prevent the hole from being formed over the given depth; and a plurality of fastening members adapted to be inserted into the fastening portion formed along the side periphery of the stopper so as to fix the stopper to a drill body.
As yet another example of the prior arts, there is provided Korean Utility Model Registration No. 20-0338095 disclosing a dental stopper drill having a chuck coupling part, a shank part, and a drill part, wherein the drill includes a stopper formed integrally thereto along the circumference thereof in a space between the shank part and the drill part in such a manner as to be protruded to a larger diameter than the shank part and the drill part, thereby allowing the drill to form a hole to a given depth.
According to the above-mentioned drills for implant surgery in the conventional practices, in the formation of a hole for placing the implant fixture into the alveolar bone, since the cutting resistance is substantially high, a small hole is first formed and is gradually expanded to a large size. As shown in FIGS. 5A to 5F, a plurality of drills having the same length as each other but different diameters from each other, that is, having a small diameter through a desired diameter are used sequentially to cut the alveolar bone and to form the implant placement hole. However, the method using the plurality of drills has some disadvantages as follows: first, since the kinds of drills and the number of drilling times are increased, the implant surgery becomes complicated and the economical load is raised; second, since the time for the implant surgery is more extended to cause the suffering experience of the patient to be severe and to also make the surgeon feel uncomfortable; third, the bone is cut to a depth of the implant placement hole to cause the amount of bone cut to be increased; fourth, the number of drills used and the manufacturing cost of the drills are all increased; and last, their durability may be weakened at the time of the repeated usage.